With the advances in technology, touch device has become a new man-machine interactive interface widely used in electronic products due to its intuitive and human nature features.
FIG. 1 is a schematic view of a conventional touch apparatus. As shown, the conventional touch apparatus 10 includes a touch panel 100 and a touch circuit chip 110. The touch panel 100 includes a plurality of driving electrodes (herein are exemplified by driving electrodes 101a˜101e) and a plurality of sensing electrodes (herein are exemplified by sensing electrodes 103a˜103e). The driving electrodes 101a˜101e and the sensing electrodes 103a˜103e are arranged in an intersection manner; and a coupling capacitor Cm is formed at each of the intersecting points resulted by the intersection of the driving electrodes 101a˜101e and the sensing electrodes 103a˜103e. The touch circuit chip 110 is configured to transmit driving signals to the driving electrodes 101a˜101e via driving lines 105 and receive sensing signals outputted from the sensing electrodes 103a˜103e via sensing lines 107, respectively. In addition, the touch circuit chip 110 is further configured to perform a comparison operation on the last-time-received sensing signals and accordingly generate a comparison result. Thus, the touch circuit chip 110 can determine whether there exists a change of the coupling capacitor according to the aforementioned comparison result and consequentially determines whether the touch panel 100 is being touched by a finger or a conductive object or not.
However, while the touch apparatus 10 is being affected by noise, the touch circuit chip 110 may generate an incorrect comparison result due to this comparison result is obtained by a comparison between the prior sensing signal without being affected by noises and the current sensing signal affected by noises; consequentially, the touch circuit chip 110 may determine whether there exists a change of the coupling capacitor according to the incorrect comparison result and mistakenly determines whether the touch panel 100 is being touched by a finger or a conductive object or not. To avoid the effect of noises, a plurality of filters are needed to be arranged in the conventional touch circuit chip 110.